mirror of https://github.com/GNOME/gimp.git
49 lines
1.5 KiB
C
49 lines
1.5 KiB
C
/* The GIMP -- an image manipulation program
|
|
* Copyright (C) 1995 Spencer Kimball and Peter Mattis
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
|
*/
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <math.h>
|
|
#include "appenv.h"
|
|
#include "color_transfer.h"
|
|
|
|
#define SQR(x) ((x) * (x))
|
|
|
|
/* for lightening */
|
|
double highlights_add[256];
|
|
double midtones_add[256];
|
|
double shadows_add[256];
|
|
|
|
/* for darkening */
|
|
double highlights_sub[256];
|
|
double midtones_sub[256];
|
|
double shadows_sub[256];
|
|
|
|
/* color transfer functions */
|
|
void
|
|
color_transfer_init ()
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < 256; i++)
|
|
{
|
|
highlights_add[i] = shadows_sub[255 - i] = (1.075 - 1 / ((double) i / 16.0 + 1));
|
|
midtones_add[i] = midtones_sub[i] = 0.667 * (1 - SQR (((double) i - 127.0) / 127.0));
|
|
shadows_add[i] = highlights_sub[i] = 0.667 * (1 - SQR (((double) i - 127.0) / 127.0));
|
|
}
|
|
}
|